csp 201604-1 折点计数

 

//小傻瓜呀，这么简单都能想麻烦
#include<iostream>
using namespace std;
int main(){
    
    int n;
    cin>>n;
    int* a=new int[n];
    for(int i=0;i<n;i++){
        cin>>a[i];
    }
    int cou=0;
    for(int i=1;i<n-1;i++){
        int b=a[i]-a[i-1];
        int c=a[i]-a[i+1];
        if(b*c>0) cou++;
    }
    cout<<cou<<endl;
    delete[] a;
    return 0;
    
    
} 

#include <cstdio>

int main() {
    int N;
    scanf("%d", &N);
    if(N < 3) {
        printf("%d", 0);
        return 0;
    }
    int cnt = 0;
    int pre, cur, next;
    scanf("%d", &pre);
    scanf("%d", &cur);
    for(int n=2; n<N; n++) {
        scanf("%d", &next);
        if(cur > pre && cur > next) cnt++;
        else if(cur < pre && cur < next) cnt++;
        pre = cur;
        cur = next;
    }
    printf("%d", cnt);
}
//https://www.cnblogs.com/meelo/p/7643345.html